Sixty years ago, the December 1956 issue of the British publication Radio Constructor carried the plans for this three transistor broadcast set. Those who built it were undoubtedly amongst the first in the British Isles to own a transistor radio.

The set was basically a crystal set, using a type 0A71 crystal diode detector, with three PNP transistors serving as audio amplifier. The transistors are identified as “Red Spot” from Henrys Radio, and are undoubtedly CK722‘s.

In place of a speaker, a crystal microphone element is used, with a capacitor in parallel which was said to soften the audio a bit. In London, the set pulled in the two local BBC broadcasts without an external antenna. For more remote areas, an external antenna, perhaps concealed in a carrying strap, could be employed. The set as shown here was pretuned to two stations, with the switch used to go from one to the other. The article noted that a more traditional variable capacitor could also be used, as shown in the schematic below.